1. Field of the Invention
The present invention relates to an apparatus for measuring an optical output of an optical pickup device disposed in an optical disk drive unit, or a magnetic field distribution of a magnetic head for generating an auxiliary magnetic field disposed in a magnetooptic disk drive unit.
2. Description of the Related Art
For example, in an optical pickup device used to record data to an optical disk drive device and reproduce these data therefrom, the optical pickup device is adjusted in operation at a forwarding time thereof from a factory such that a quantity level of a laser beam outputted at recording and reproducing times of the data is equal to a predetermined level.
It is therefore necessary to detect an optical output of the optical pickup device so as to adjust this optical output. In general, the optical output of the optical pickup device is measured by the following methods having some problems.
In a first measuring method of the optical output, it is troublesome to disassemble a optical disk drive unit so as to measure the optical output. It is difficult to provide a reliable measured value of the optical output since there is great dispersion in a measuring position of the optical output. Further, it is necessary to pay attention to the removal of an influence of disturbance light around the optical disk drive unit.
In a second measuring method of the optical output, a jig is attached to a turn table so as to measure the optical output. However, the jig is unstably attached to the turn table so that it is difficult to provide a reliable measured value of the optical output.
In a general method for measuring the intensity of a magnetic field, no intensity of the magnetic field is measured in a state in which magnetic head is really attached to a magnetooptic disk drive device. Accordingly, measured results of the intensity of the magnetic field are uncertain and a measuring operation of this magnetic field intensity is troublesome.